1. Field of the Invention
The present invention relates to a printer for printing on roll paper, a control method for the printer, and a computer-readable medium embodying a program of instructions for implementing the control method. More particularly, the invention relates to novel way of controlling advancement of the roll paper after printing, which may be embodied in a printer, a control method for such a printer, and/or a computer-readable medium containing an instruction program for the method.
2. Description of the Related Art
Printers used in ATM machines, for example, typically print to roll paper or other type of continuous recording medium, and then cut the printed form to an appropriate length using an automatic paper cutting mechanism. Such printers are often installed in unattended locations, making it very important to minimize the potential for problems arising in conjunction with normal use.
Controlling advancement of the printed paper must be carefully considered in this type of printer. In this type of printer the leading edge of the paper, both after printing is terminated and while printing is in progress, is gradually advanced from the paper exit by the operation that advances the paper for printing. If the user pulls on the end of the paper projecting from the paper exit before the paper is cut by the automatic paper cutting mechanism, print defects or a paper jam can occur.
To prevent such problems, advancement by the ejection rollers provided near the paper exit is temporarily stopped so that the leading edge of the paper does not project from the paper exit. Once cutting the paper is then completed, the ejection rollers resume advancing the form to eject the paper from the paper exit. A problem with this type of printer is that the user must wait to remove the paper because paper advancement does not start until after both printing and then cutting the paper are finished. Another problem with such printers is that it is possible for the paper to be cut too short when little information is printed to the paper, resulting in the paper being cut before the leading edge is advanced to the ejection rollers near the paper exit. In such cases the form may not be ejected from the paper exit and thus be left inside the printer.
An object of the present invention is therefore to resolve the above noted problems by providing a printer that can provide a printed form to the user as soon as possible after printing is terminated, a control method for such a printer, and computer-readable medium carrying a computer program for executing the method.
A further object of the present invention is to provide a printer, a printer control method and instruction program medium that enable a cut form to be reliably ejected from the paper exit even when little content is printed to the paper.
To achieve these objects, the present invention provides, in one aspect, a printer control method. The method comprises the steps of (a) printing to a print medium; (b) transporting the print medium printed in step (a) toward a print medium ejection opening; (c) holding a leading end part of the print medium at a predetermined position upstream of the print medium ejection opening to stop the transportation of the print medium, so as to produce slack in the print medium; (d) cutting the print medium to separate the print medium printed in step (a) from the remaining part of the print medium; and (e) releasing, before completion of step (d), the holding of the print medium in step (c) to resume transporting the print medium toward the print medium ejection opening.
Printer throughput can be improved by controlling the printer in this way because form ejection starts without waiting for the paper cutting operation to finish.
While ejecting the paper starts with this control method before the roll paper is completely cut, prohibiting paper ejection while printing is in progress produces an accumulation of paper (slack) inside the printer in the paper transportation path between the paper cutter and the paper exit. Therefore, even if the leading end of the paper is exposed from the paper exit before paper cutting is finished and the user pulls on the exposed leading end, this will not immediately cause a paper cutting defect or contribute to a paper jam.
Step (e) in the above printer control method preferably includes the steps of (i) measuring an amount of slack produced in the print medium; (ii) comparing the amount of slack measured in step (i) with a specific value; (iii) resuming transportation of the print medium toward the print medium ejection opening at a first speed if the amount of slack measured in step (i) is more than the specific value; and (iv) resuming transportation of the print medium toward the print medium ejection opening at a second speed that is slower than the first speed if the amount of slack measured in step (i) is less than the specific value.
Preferably this control method additionally comprises the steps of detecting whether the print medium has reached the print medium stopping position near the print medium ejection opening before carrying out step (d); and advancing the print medium to the stopping position if, based on the result of detecting step, the print medium has not reached the stopping position.
By thus providing these steps the printed form can be reliably ejected from the printer even when the area printed on the paper is short.
Preferably, the stopping of the print medium in step (c) is accomplished by stopping rotation of an ejection roller disposed upstream of the print medium ejection opening, and the releasing and resuming of print medium transportation in step (e) is accomplished by starting rotation of the ejection roller.
The present invention may be embodied in a printer comprised so as to accomplish the printer control method described above. The present invention may also be embodied in a computer-readable medium that carries a program of instructions for implementing the control method.
Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings.